How do you connect two DIFFERENT LINES?

How do you connect two DIFFERENT LINES?

How do you connect two DIFFERENT LINES?

I'm trying to connect two nodes - one on one line, and one on the other, I'm used to flexi-sign software, all you have to do is click on one node, hold your shift key while clicking on the other node to select both nodes at once then hit your join key and they connect, I see the icons to connect the nodes, but I can't select both at once, so they stay grayed out - what am I doing wrong??? Any help sure would be appreciated! Thanks in advance!